It is known that the filling of the tanks of a wide-bodied aircraft on the ground is managed automatically by a computer that computes, as a function of the quantity of fuel necessary in order for said aircraft to accomplish its mission, the various weights of fuel to be poured into the various tanks in order for, at each instant of filling, the center of gravity of said aircraft to be kept in an authorized range of positions along the longitudinal axis of said aircraft.
Thus, good centering of said aircraft is obtained continuously, thereby ensuring satisfactory stability and enabling it, after filling, to be easily controllable.
It is known, moreover, that a modern civil aircraft comprises at least one fuel tank disposed in the tail and that, in the case of a wide-bodied aircraft, the capacity of this tail tank is considerable. Furthermore, if this aircraft is of the wide-bodied type, the distance separating this tail tank from the center of the aircraft is large. Now, this distance constitutes the lever arm with which the weight of fuel contained in the tail tank exerts a moment on said aircraft. This moment may therefore be very considerable and exert a strong aircraft destabilizing action. The filling of the tail tank with fuel is therefore critical for the stability of the aircraft.